Image-capturing unit

ABSTRACT

Provided is an image-capturing unit including an image-capturing chip that includes a first surface having a pixel and a second surface that is on an opposite side of the first surface and has provided thereon an output section that outputs a pixel signal read from the pixel; a transparent substrate that is arranged facing the first surface and includes a wire pattern; a mounting substrate that is arranged facing the second surface and supports the image-capturing chip; and a relay section that is arranged on the mounting substrate and relays, to the wire pattern, the pixel signal output from the output section. Also provided is an image-capturing apparatus including the image-capturing unit described above.

This application is a Continuation of U.S. patent application Ser. No.15/651,708, filed Jul. 17, 2017, which is a Continuation of U.S. patentapplication Ser. No. 14/600,551 filed Jan. 20, 2015, which is acontinuation of PCT/JP2013/004420 filed Jul. 19, 2013, which in turnclaims priority from Japanese Patent Application 2012-161365 filed Jul.20, 2012. The disclosures of each of these applications are incorporatedherein by reference in their entirety.

BACKGROUND 1. Technical Field

The present invention relates to an image-capturing unit, animage-capturing apparatus, and an image-capturing unit manufacturingmethod.

2. Related Art

An image-capturing unit is known that has a COG (Chip On Glass)structure. The COG image-capturing unit is directly connected to atransparent substrate and an image-capturing chip, using a flip-chipimplementation technique.

Patent Document 1: Japanese Patent Application Publication No.2009-246152

With the flip-chip implementation, when the transparent substrate andthe image-capturing chip are heated or cooled, warping occurs in theimage-capturing chip. As a result, this warping causes stress in thebumps of the image-capturing chip, and there is a concern that the bumpswould be damaged.

SUMMARY

According to a first aspect of the present invention, provided is animage-capturing unit comprising an image-capturing chip that includes afirst surface having a pixel and a second surface that is on an oppositeside of the first surface and has provided thereon an output sectionthat outputs a pixel signal read from the pixel; a transparent substratethat is arranged facing the first surface and includes a wire pattern; amounting substrate that is arranged facing the second surface andsupports the image-capturing chip; and a relay section that is arrangedon the mounting substrate and relays, to the wire pattern, the pixelsignal output from the output section.

According to a second aspect of the present invention, provided is animage-capturing unit comprising an image-capturing chip that has a lightreceiving surface and a mounting surface that is on an opposite side ofthe light receiving surface; a mounting substrate that is arrangedfacing the mounting surface of the image-capturing chip and includes awire pattern that is connected to the image-capturing chip; atransparent substrate that is arranged facing the light receivingsurface of the image-capturing chip; and a connecting section thatconnects the transparent substrate and the wire pattern of the mountingsubstrate.

According to a third aspect of the present invention, provided is animage-capturing apparatus comprising the image-capturing unit describedabove.

According to a fourth aspect of the present invention, provided is animage-capturing unit manufacturing apparatus comprising forming, on asecond surface of a wafer, an output section that is electricallyconnected to a pixel formed on the wafer and used for outputting a pixelsignal that is an output of the pixel; arranging a mounting substratefacing the second surface; forming a first surface that inputs incidentlight to the pixel, by grinding a surface of the wafer that is on anopposite side of the second surface; separating, into individual chipunits, the wafer and the mounting substrate; and arranging a transparentsubstrate, which has a wire pattern provided thereon in a peripheralregion that is outside of a region corresponding to the pixel, in amanner to face the first surface and cover the pixel, and connecting thewire pattern and the output section with a relay section.

The summary clause does not necessarily describe all necessary featuresof the embodiments of the present invention. The present invention mayalso be a sub-combination of the features described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a configuration of an image-capturing unit according to anembodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an image-capturingapparatus according to an embodiment of the present invention.

FIGS. 3A to 3E are views for describing the image-capturing unitmanufacturing method.

FIGS. 4A to 4C are views for describing the image-capturing unitmanufacturing method.

FIG. 5 shows another configuration of an image-capturing unit.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, some embodiments of the present invention will bedescribed. The embodiments do not limit the invention according to theclaims, and all the combinations of the features described in theembodiments are not necessarily essential to means provided by aspectsof the invention.

FIG. 1 shows a configuration of an image-capturing unit 10 according toan embodiment of the present invention. The image-capturing unit 10 isan image-capturing unit having a COG (Chip On Glass) structure. Theimage-capturing unit 10 includes an image-capturing chip 100, atransparent substrate 200, a mounting substrate 300, a signal processingchip 400, and a heat releasing member 500.

The image-capturing chip 100 is a backside illumination MOS imagesensor. The image-capturing chip 100 includes a pixel region 101 on afirst surface 111 side, which is the light receiving surface side. Thepixel region 101 includes a plurality of pixels that performphotoelectric conversion on incident light. An output terminal 102,which is an output section for outputting a pixel signal that has beenread from the pixels, is arranged on a second surface 112, which is themounting surface and on the opposite side of the first surface 111. Theoutput terminal 102 is arranged extending outward at the ends of thesecond surface 112. The image-capturing chip 100 includes a columncircuit that has an initial stage amplifier in a region outside of thepixel region 101.

The transparent substrate 200 is a cover glass that is formed byborosilicate glass, quartz glass, non-alkali glass, or heat-resistantglass, for example. The transparent substrate 200 is arranged facing thefirst surface 111 of the image-capturing chip 100, and covers the pixelregion 101. The transparent substrate 200 includes a first wire pattern201, which relays the pixel signal to the signal processing chip 400, onthe surface region thereof facing the image-capturing chip 100.

The electrode pad 202 provided on the first wire pattern 201 iselectrically connected to the output terminal 102 of the image-capturingchip 100, via a first bump 601. In the present embodiment, the firstbump 601 functions as at least a portion of a relay section that relaysthe pixel signal output from the output terminal 102 to the first wirepattern 201. The connecting section between the electrode pad 202 andthe output terminal 102 is attached by an adhesive agent 701 formed tosurround this connecting section. The adhesive agent 701 is also formedto surround the periphery of the image-capturing chip 100. In this way,the space between the pixel region 101 and the transparent substrate 200is sealed. In other words, the adhesive agent 701 functions as a sealingmember. Furthermore, the transparent substrate 200 includes a secondwire pattern 204 that relays the pixel signal to the outside.

The mounting substrate 300 is arranged facing the second surface 112 ofthe image-capturing chip 100, and supports the image-capturing chip 100.Accordingly, the mounting substrate 300 serves as a support substrate.The linear expansion coefficient of the mounting substrate 300 is lessthan the linear expansion coefficient of the transparent substrate 200.Furthermore, the difference between the linear expansion coefficient ofthe mounting substrate 300 and the linear expansion coefficient of thetransparent substrate 200 may be less than the difference between thelinear expansion coefficient of the image-capturing chip 100 and thelinear expansion coefficient of the transparent substrate 200.

A wire pattern may be formed on the mounting substrate 300. If a wirepattern is formed on the mounting substrate 300, the pixel signal outputfrom the output terminal 102 is transmitted to the first wire pattern201 of the transparent substrate 200 through the wire pattern of themounting substrate 300. In this case, the first bump 601 can be treatedas the connecting section that connects the wire pattern of the mountingsubstrate 300 to the transparent substrate 200.

In the image-capturing unit 10 of the present embodiment, theimage-capturing chip 100 and the transparent substrate 200 are notdirectly bump-bonded to each other, and the mounting substrate 300having a linear expansion coefficient between the linear expansioncoefficients of the image-capturing chip 100 and the transparentsubstrate 200 is interposed between the image-capturing chip 100 and thetransparent substrate 200. By interposing the mounting substrate 300between the image-capturing chip 100 and the transparent substrate 200,the difference between the linear expansion coefficients of thetransparent substrate 200 and the mounting substrate 300 can be madesmall relative to the difference between the linear expansioncoefficients of the image-capturing chip 100 and the transparentsubstrate 200. Accordingly, the stress placed on the first bump 601 canbe decreased.

Since the image-capturing chip 100 is a backside illumination MOS imagesensor, the back surface of the image-capturing chip undergoes grindingduring manufacturing. On the other hand, there are cases where thesignal processing chip 400 does not undergo grinding duringmanufacturing. Accordingly, the image-capturing chip 100 and the signalprocessing chip 400 have different thicknesses. Therefore, in order toarrange the heat releasing member in a manner to contact both theimage-capturing chip 100 and the signal processing chip 400, it isnecessary to perform step machining on the heat releasing memberaccording to the difference in thickness between the image-capturingchip 100 and the signal processing chip 400.

In the image-capturing unit 10 of the present embodiment, the mountingsubstrate 300 is arranged facing the second surface 112 of theimage-capturing chip 100. The thickness of this mounting substrate 300is adjusted according to the difference in thickness between the signalprocessing chip 400 and the image-capturing chip 100. Accordingly, byarranging the mounting substrate 300 on the second surface 112 side ofthe image-capturing chip 100, the mounting substrate 300 and the signalprocessing chip 400 can be arranged in the same plane on the heatreleasing member 500.

A heat conducting material may be applied between the image-capturingchip 100 and the mounting substrate 300. The heat conducting materialcan be resin with greater thermal conductivity than air. In this way,the heat generated by the column circuit of the image-capturing chip 100can be efficiently released to the mounting substrate 300 side. The heatconducting material may fill the entire region between theimage-capturing chip 100 and the mounting substrate 300. In this case,the contact surface area between the heat conducting material and themounting substrate 300 increases, and therefore the thermal resistancecan be reduced. Accordingly, the heat releasing effect can be furtherimproved.

The signal processing chip 400 includes a processing circuit thatprocesses the pixel signal input through the first wire pattern 201. Thenumber of signal processing chips is determined as needed according tothe method used to read the pixel signal. In the present embodiment,2-channel reading is adopted as the pixel signal reading method.Accordingly, there are two signal processing chips.

The signal processing chips 400 are arranged in parallel with theimage-capturing chip 100. More specifically, the signal processing chips400 are arranged in a peripheral region of the transparent substrate200, which is outside the region covered by the pixel region 101. Thesignal processing chips 400 are arranged at a position distanced fromthe image-capturing chip 100, with the second bump 602, the transparentsubstrate 200, and the first bump 601 interposed therebetween.Accordingly, the heat generated by the signal processing chip 400 istransferred from the second bump 602 to the transparent substrate 200and then from the transparent substrate 200 to the first bump 601, andthen reaches the image-capturing chip 100. Compared to a case in whichthe image-capturing chip and the signal processing chips are layered,the heat transfer path from the signal processing chips 400 to theimage-capturing chip 100 is longer, and therefore the heat transferredfrom the signal processing chips 400 to the image-capturing chip 100 canbe reduced. Accordingly, the temperature increase of the pixel regioncaused by the heat from the signal processing chips 400 can berestricted, thereby enabling a decrease in the dark current. As aresult, a decrease in image quality can be prevented.

Each signal processing chip 400 includes an electrode pad 401 and anelectrode pad 402. The electrode pad 401 is electrically connected tothe electrode pad 203 of the first wire pattern 201, via the second bump602. The connecting section between the electrode pad 401 and theelectrode pad 203 is attached by the adhesive agent 702 formed tosurround this connecting section. The electrode pad 402 is electricallyconnected to the electrode pad 205 of the second wire pattern 204, viathe third bump 603. The connecting section between the electrode pad 402and the electrode pad 205 is attached by the adhesive agent 703 formedto surround this connecting section.

Furthermore, the second wire pattern 204 is electrically connected to aflexible substrate, which is not shown, and transmits to the outside viathe flexible substrate. With the configuration described above, thepixel signal of the pixel region is output to the output terminal 102from the non-incident surface side of the image-capturing chip 100, thentransmitted to the incident surface side by the first bump 601, and thentransmitted to the outside through the transparent substrate 200 and thesignal processing chip 400.

The heat releasing member 500 is formed by a material with high thermalconductivity, such as metal, for example. The metal used can be copper,a nickel alloy, iron, aluminum, or the like. The heat releasing member500 is arranged in contact with the surface of the mounting substrate300 that is on the opposite side of the surface facing theimage-capturing chip 100. The heat releasing member 500 also contactsthe surface of the signal processing chip 400 that is on the oppositeside of the surface to which the first wire pattern 201 is connected.Since the heat releasing member 500 contacts both the image-capturingchip 100 and the signal processing chip 400, both the heat generated bythe image-capturing chip 100 and the heat generated by the signalprocessing chip 400 can be released. The heat releasing member 500 maybe formed with a fin shape. In this way, the heat releasing surface areaof the heat releasing member 500 increases, and therefore the heatreleasing characteristic can be further improved.

The height of the first bump 601 is greater than the height of thesecond bump 602 and the third bump 603, by the thickness of theimage-capturing chip 100. The present embodiment describes an example inwhich the thickness of the mounting substrate 300 is adjusted accordingto the difference in thickness between the signal processing chip 400and the image-capturing chip 100, but when considering the relationshipbetween the first bump 601 and the second bump, it can also be said thatthe thickness of the mounting substrate 300 is adjusted according to thedifference between the thickness of the first bump 601 and the combinedthickness of the signal processing chip 400 and the second bump 602. Inother words, the thickness of the mounting substrate 300 is adjustedsuch that the sum of the thickness of the signal processing chip 400 andthe thickness of the second bump 602 is equal to the sum of thethickness of the mounting substrate 300 and the thickness of the firstbump 601. By adjusting the thickness of the mounting substrate 300 inthis way, the image-capturing chip 100 and the signal processing chip400 can be arranged in the same plane on the heat releasing member 500.Accordingly, there is no need to perform step machining on the heatreleasing member 500. The heat releasing member 500 is attached to thebody of an image-capturing apparatus, which is described further below.

In a case where a backside illumination MOS image sensor is used as theimage-capturing chip, if a configuration is adopted in which the signalprocessing chip is layered on the second surface side of theimage-capturing chip, a TSV (Through-Silicon Via) for transmitting thepixel signal to the signal processing chip is formed on theimage-capturing chip. In this case, the width of the image-capturingchip is increased by the width of the TSV formed.

In the image-capturing unit 10 of the present embodiment, the outputterminal 102 extends to the outside and the output terminal 102 of theimage-capturing chip 100 and the first wire pattern of the signalprocessing chip 400 are electrically connected via the transparentsubstrate 200. Since there is no TSV formed in the image-capturing chip100, the image-capturing chip 100 can be made smaller.

FIG. 2 is a block diagram showing a configuration of an image-capturingapparatus according to an embodiment of the present invention. Theimage-capturing apparatus 800 includes an image-capturing lens 820 thatserves as an image capturing optical system, and the image-capturinglens 820 guides subject light that is incident thereto along the opticalaxis OA to the image-capturing unit 10. The image-capturing lens 820 maybe an exchangeable lens that can be attached to and removed from theimage-capturing apparatus 800. The image-capturing apparatus 800primarily includes the image-capturing unit 10, a system control section801, a driving section 802, a work memory 804, a recording section 805,and a display section 806.

The image-capturing lens 820 is formed by a plurality of optical lensgroups, and focuses the subject light from a scene at a region near afocal plane. FIG. 2 represents the image-capturing lens 820 as a singlevirtual lens arranged near the pupil. The driving section 802 is acontrol circuit that performs dynamic control of the image-capturingunit 10, region control, charge accumulation control, and the like,according to instructions from the system control section 801.

The image-capturing unit 10 passes the pixel signal to the imageprocessing section 811 of the system control section 801. The imageprocessing section 811 performs various types of image processing, withthe work memory 804 as a work space, to generate the image data. Forexample, when generating image data with a JPEG file format, the imageprocessing section 811 performs white balance processing, gammaprocessing, or the like and then performs a compression process. Thegenerated image data is recorded in the recording section 805 and alsoconverted into a display signal and displayed in the display section806.

FIGS. 3A to 3E are views for describing the image-capturing unit 10manufacturing method. Specifically, FIGS. 3A to 3E show steps ofprocessing at the wafer level. First, as shown in FIG. 3A, the wafer110, on which is formed a plurality of pixel regions 101 that eachinclude a plurality of pixels for photoelectrically converting incidentlight, is prepared and the output terminal 102, which is electricallyconnected to the pixel region 101 and used for outputting the pixelsignal that is the output of the pixels, is formed on the second surface112 of the wafer 110 (terminal formation step).

Next, as shown in FIG. 3B, the mounting substrate 310 is arranged facingthe second surface 112 (mounting substrate arrangement step). In thisway, the output terminal 102 is in a state of being sandwiched betweenthe wafer 110 and the mounting substrate 310.

Next, as shown in FIG. 3C, grinding is performed on the surface of thewafer that is on an opposite side of the second surface 112, and thefirst surface 111 is formed to input the incident light to the pixels(grinding step). By performing this grinding, the thickness of the wafer120 after grinding is less than that of the wafer 110 before grinding.The grinding method can be CMP (Chemical Mechanical Polishing) or BG(Back Grinding).

Next, as shown in FIG. 3D, in a state where the mounting substrate 310side is arranged at the bottom of the drawing, partial etching isperformed on the regions between adjacent pixel regions 101 on thewafer. As a result, the output terminal 102 formed on the second surface112 is exposed.

Next, the wafer and the mounting substrate are cut into separate circuitregions that each include a pixel region 101. In this way, as shown inFIG. 3E, individual pieces are formed by separating the wafer into chipunits (separation process).

FIGS. 4A to 4C are views for describing the image-capturing unit 10manufacturing method. Specifically, FIGS. 4A to 4C show steps performedafter the separation. The steps after the separation process are appliedin the same manner to each image-capturing chip, and therefore thisdescription focuses on a single image-capturing chip.

As shown in FIG. 4A, the transparent substrate 200, which has the firstwire pattern 201 arranged thereon in the peripheral region that isoutside of the region corresponding to the pixels, is arranged to facethe first surface 111 of the image-capturing chip 100 and cover thepixels, and the first wire pattern 201 and the output terminal 102 areconnected (transparent substrate arrangement step). Specifically theadhesive agent 701 is formed on the output terminal 102 of theimage-capturing chip 100 using a dispenser. A heat-curable resin can beused as the adhesive agent 701. The image-capturing chip 100 on whichthe adhesive agent 701 is formed is aligned with the transparentsubstrate 200 on which the first bump 601 has been formed in advance onthe electrode pad 202 of the first wire pattern 201, and then thetransparent substrate 200 is affixed on the image-capturing chip 100.The affixing of the image-capturing chip 100 and the transparentsubstrate 200 is performed in a heated state.

Next, as shown in FIG. 4B, the signal processing chip 400 including theprocessing circuit that processes the pixel signal is arranged on thetransparent substrate 200 and connected to the first wire pattern 201and the second wire pattern 204 (signal processing chip arrangementstep). Specifically, the adhesive agent 702 is formed on the electrodepad 401 of the signal processing chip 400 using a dispenser. In the samemanner, the adhesive agent 703 is formed on the electrode pad 402 of thesignal processing chip 400 using a dispenser. The signal processing chip400 on which the adhesive agent 702 and the adhesive agent 703 areformed is aligned with the transparent substrate 200, on which thesecond bump 602 and the third bump 603 have been formed in advancerespectively on the electrode pad 203 and the electrode pad 205, andthen the transparent substrate 200 is affixed on the signal processingchip 400. The affixing of the signal processing chip 400 and thetransparent substrate 200 is performed in the heated state.

Next, as shown in FIG. 4C, the heat releasing member 500 is arranged ina manner to contact the surface of the mounting substrate 300 on theopposite side of the image-capturing chip 100 side surface and thesurface of the signal processing chip 400 on the opposite side of thetransparent substrate 200 side surface.

With the image-capturing unit 10 manufacturing method of the presentembodiment, the wafer is etched to expose the output terminal 102, andthen the output terminal 102 and the electrode pad 202 are bump-bonded.Since there is no TSV requiring complicated processing formed on theimage-capturing chip 100, the overall process can be simplified.

In the above description, the stress is reduced by including themounting substrate 300 with a linear expansion coefficient between thelinear expansion coefficients of the image-capturing chip 100 and thetransparent substrate 200. Even if the mounting substrate 300 itselfdoes not have a linear expansion coefficient between the linearexpansion coefficients of the image-capturing chip 100 and thetransparent substrate 200, a film having a linear expansion coefficientbetween the linear expansion coefficients of the image-capturing chip100 and the transparent substrate 200 may be formed on the mountingsubstrate 300. By forming a film that as a characteristic of pulling ina direction opposite the direction in which the image-capturing chip 100pulls, deformation of the image-capturing unit due to heating or coolingcan be restricted. This film can be realized as a SiON-type film. ThisSiON-type film can be formed through CVD (Chemical Vapor Deposition).The characteristics of the film can be changed by changing the ratio ofnitrogen and oxygen in the SiON-type film or by changing the formationconditions of this film, for example.

In the above description, one heat releasing member 500 contacts boththe image-capturing chip 100 and the signal processing chip 400, butinstead an independent heat releasing member 500 may be provided foreach chip. In this way, the size of the heat releasing member 500 can beoptimized according to the amount of heat generated by each chip. Theamount of heat generated by the signal processing chip 400 is greaterthan the amount of heat generated by the image-capturing chip 100, andtherefore the surface area of the heat releasing member arranged on thesignal processing chip 400 is preferably greater than the surface areaof the heat releasing member arranged on the image-capturing chip 100.For example, the heat releasing member arranged on the signal processingchip 400 may be formed with a fin shape.

Furthermore, a third wire pattern for relaying the pixel signal outputfrom the output terminal 102 to the first wire pattern 201 may be formedon the front surface of the mounting substrate 300. In this case, theoutput terminal 102 need not extend outside the image-capturing chip100. In other words the output terminal 102 is arranged on thenon-incident surface of the image-capturing chip 100 and the third wirepattern is bump-bonded to the output terminal 102. The third wirepattern and the first wire pattern 201 are then connected by the firstbump 601. The output terminal 102 and the first wire pattern 201 areconnected via the first bump 601 and the third wire pattern. In otherwords the first bump 601 and the third wire pattern function as a relaysection that relays the pixel signal output from the output terminal 102to the first wire pattern 201. Furthermore, the output terminal 102 andthe first wire pattern can be electrically connected through wirebonding.

In the above description, the pixel region 101 and the processingcircuit for processing the pixel signal are formed on separate chips,but may instead be formed on the same chip. FIG. 5 shows anotherconfiguration of an image-capturing unit 10. The image-capturing unit 10shown in FIG. 5 includes an image-capturing chip 100, a transparentsubstrate 200, a mounting substrate 300, a heat releasing member 500,and a flexible substrate 710. The image-capturing chip 100 shown in FIG.5 includes a pixel region 101 on the first surface 111 side. An outputterminal 102, which is the output section for outputting the pixelsignal read from the pixels, is arranged on a second surface 112, whichis the surface facing away from the first surface 111. The outputterminal 102 is arranged to extend outward at both ends of the secondsurface 112. The image-capturing chip 100 includes a column circuit thathas an initial stage amplifier in a region outside of the pixel region101. Furthermore, the image-capturing chip 100 includes a processingcircuit for processing the pixel signal.

In the image-capturing unit 10 shown in FIG. 5 as well, theimage-capturing chip 100 and the transparent substrate 200 are notdirectly bump-bonded to each other, and the mounting substrate 300having a linear expansion coefficient between the linear expansioncoefficients of the image-capturing chip 100 and the transparentsubstrate 200 is interposed between the image-capturing chip 100 and thetransparent substrate 200. By interposing the mounting substrate 300between the image-capturing chip 100 and the transparent substrate 200,the difference between the linear expansion coefficients of thetransparent substrate 200 and the mounting substrate 300 can be madesmall relative to the difference between the linear expansioncoefficients of the image-capturing chip 100 and the transparentsubstrate 200. Accordingly, the stress placed on the first bump 601 canbe decreased.

In the image-capturing unit 10 shown in FIG. 5, the flexible substrate710 includes an electrode pad 401 and an electrode pad 402. Theelectrode pad 401 is electrically connected to the electrode pad 203 ofthe first wire pattern 201, via the second bump 602. The connectingsection between the electrode pad 401 and the electrode pad 203 isattached by the adhesive agent 702 formed to surround this connectingsection. The electrode pad 402 is electrically connected to theelectrode pad 205 of the second wire pattern 204, via the third bump603. The connecting section between the electrode pad 402 and theelectrode pad 205 is attached by the adhesive agent 703 formed tosurround this connecting section. With the image-capturing unit 10 shownin FIG. 5, the pixel signal of the pixel region is output to the outputterminal 102 from the non-incident surface side of the image-capturingchip 100, and then processed by the processing circuit in theimage-capturing chip 100. After this, the pixel signal is transmitted tothe incident surface side by the first bump 601, and then transmitted tothe outside through the transparent substrate 200 and the flexiblesubstrate 710.

In the above description, the output terminal 102 is formed on thesecond surface 112 side of the image-capturing chip 100, but may insteadbe formed on the first surface 111 side.

While the embodiments of the present invention have been described, thetechnical scope of the invention is not limited to the above describedembodiments. It is apparent to persons skilled in the art that variousalterations and improvements can be added to the above-describedembodiments. It is also apparent from the scope of the claims that theembodiments added with such alterations or improvements can be includedin the technical scope of the invention.

Even if the process flow is described using phrases such as “first” or“next” in the claims, embodiments, or diagrams, it does not necessarilymean that the process must be performed in this order.

What is claimed is:
 1. An image-capturing unit comprising: a substrateto which light is inputted; a film on which an image-capturing chip towhich light from the substrate is inputted is arranged; and a connectingsection that connects the substrate and the film, wherein theimage-capturing chip, the substrate and the film have different thermalexpansion coefficients, and a difference between the thermal expansioncoefficients of the film and the substrate is smaller than a differencebetween the thermal expansion coefficients of the image-capturing chipand the substrate.
 2. The image-capturing unit according to claim 1,wherein the substrate has a wiring, and the connecting sectionelectrically connects the image-capturing chip and the wiring.
 3. Theimage-capturing unit according to claim 2, wherein the image-capturingchip includes: a pixel that includes a photoelectric conversion sectionthat converts light from the substrate into charge; and an outputsection that outputs a signal from the pixel.
 4. The image-capturingunit according to claim 3, wherein the image-capturing chip includes afirst surface facing the substrate and a second surface facing the film,a plurality of the pixels are arranged on the first surface, and theoutput section is arranged on the second surface.
 5. The image-capturingunit according to claim 2, wherein the connecting section includes abump that electrically connects the image-capturing chip and the wiring.6. The image-capturing unit according to claim 3, further comprising asignal processing chip that is connected to the wiring and processes asignal outputted from the pixel.
 7. The image-capturing unit accordingto claim 6, wherein the signal processing chip is arranged in parallelwith the image-capturing chip.
 8. The image-capturing unit according toclaim 1, further comprising a heat conducting agent that conducts heatfrom the image-capturing chip.
 9. The image-capturing unit according toclaim 1, further comprising a heat releasing member that conducts heatfrom the image-capturing chip.
 10. The image-capturing unit according toclaim 1, further comprising a sealing member that seals a space betweenthe image-capturing chip and the substrate.
 11. An image-capturingapparatus comprising the image-capturing unit according to claim 1.